Mobile multimedia Java framework application program interface

ABSTRACT

A mobile multimedia framework API is provided that is capable of operation in mobile hardware devices. The mobile multimedia framework API includes a playback interface, controls, an event listener, an error list, exceptions, events, control types, and protocol handlers. Advantageously, a memory size of the mobile multimedia framework API is less than 100 kilobytes.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication having Ser. No. 60/285,568, filed on Apr. 20, 2001, entitled“Method and Apparatus For a Mobile Multimedia Java Framework,” which ishereby incorporated by reference. This application is also related toU.S. patent application Ser. No. 09/930,850, filed Aug. 15, 2001, andentitled “Method and Apparatus for a Mobile Multimedia Java Framework,”which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to multimedia frameworks, and moreparticularly multimedia frameworks having a reduced footprint andcapable of operating on mobile computing devices.

2. Description of the Related Art

Java, originally developed by Sun Microsystems, is an object-oriented,multi-threaded, portable, platform-independent, secure programmingenvironment used to develop, test and maintain software programs. Javaprograms have found extensive use on the World Wide Web, which is theInternet's multimedia information retrieval system. These programsinclude full-featured interactive, standalone applications, as well assmaller programs, known as applets, that run in a Java-enabled Webbrowser or applet viewer.

Recently, the computer industry has sought to add computer processingand communications capabilities to devices other than what wouldnormally be considered a traditional computer. Such devices are quitevaried and include, for example, personal digital assistants (PDAs),smartphones, cellular phones, desktop screen phones, in-vehicle devices,vehicle traffic lights, kiosks, business organizers (e.g., IBMWorkPadT.TM., PalmPilot.TM., and the like), computer peripherals (suchas printers, fax machines, and the like), handheld or palmtop computingdevices, and the like. For convenience, these devices, as a class, arereferred to herein as “pervasive computing” clients as they are devicesthat are designed to be connected to servers in a computer network andused for computing purposes regardless of their location.

Palmtop computers and the like are now being proposed as pervasivecomputing devices for use in an automobile. In-vehicle navigationsystems, of course, are well-known. Representative systems are describedin U.S. Pat. Nos.: 5,121,326, 5,191,532 and 5,792,109. U.S. Pat. No.5,121,326 describes a navigation system that displays a general map ofthe driver's location. As the driver approaches an intersection, thedisplay provides a detailed map of the intersection to provide furtherguidance to the driver. In U.S. Pat. No. 5,191,532, a navigation systemis disclosed where driving directions can be provided even though theuser's exact destination is not listed in the systems database. Certaingeographic features such as cities and landmarks are used to approximatethe destination for purposes of providing directions. In U.S. Pat. No.5,729,109, the inventors provide a vehicle navigation system that usesspeech generation to give spoken directions when the driver isapproaching an intersection.

However, these mobile devices are often unable to run many multimediaapplications. Although desktop computers are designed to handle thelarge processing and memory requirements of multimedia applications,most mobile computing devices do not have the processing power or memorydemanded by these applications.

One reason for the large processing and memory requirements formultimedia applications is the application program interface (API)required by the underlying multimedia framework called by theapplications, often 2–3 megabytes in size. The API is a language andmessage format used by an application program to communicate with theoperating system or some other system or control program such as adatabase management system (DBMS) or communications protocol. APIs areimplemented by writing function calls in the program, which provide thelinkage to the required subroutine for execution. Thus, an API impliesthat some program module is available in the computer to perform theoperation or that it must be linked into the existing program to performthe tasks.

FIG. 1 is a diagram showing a prior art Java media system 100. The Javamedia system 100 includes a desktop computer 102 having a media player104 coupled to the Internet 106 via a network communication protocol.The processing power of desktop computer 102 is very large compared tothat of a mobile computing device, such as a PDA. As such, the desktopcomputer 102 can efficiently play media files using the installed mediaplayer 104. However, as mentioned above, mobile computing devices suchas a PDA do not have the processing power or memory requirements neededby conventional Media framework APIs and related implementations. Thus,mobile devices generally cannot run conventional media players createdusing conventional media framework APIs.

In view of the foregoing, there is a need for systems and methodsproviding mobile multimedia frameworks capable of operating on mobilecomputing devices. The systems and methods should provide a multimediaframework capable of operating on mobile devices having reducedprocessing capability, such as cell phones, PDAa, and Java-enabled car“Telematics”.

SUMMARY OF THE INVENTION

Broadly speaking, the present invention fills these needs by providing amobile multimedia framework having a reduced memory footprint. In oneembodiment, a mobile multimedia framework API capable of operation inmobile hardware devices is disclosed. The mobile multimedia frameworkAPI consists of a playback interface, controls, an event listener, anerror list, exceptions, events, control types, and protocol handlers.Advantageously, a memory size of the mobile multimedia framework API isless than 100 kilobytes.

In another embodiment, a mobile multimedia framework API capable ofoperation in mobile hardware devices is disclosed. The mobile multimediaframework API comprises a playback interface consisting of a managerAPI, a package manager API, a player API, a time API, a time base API, asystem time base API, and a media locator API. In addition, an eventlistener interface and a protocol handler interface are included. Asabove, the memory size of the mobile multimedia framework API is lessthan 100 kilobytes.

In a further embodiment, a mobile multimedia framework API capable ofoperation in mobile hardware devices is disclosed. The mobile multimediaframework API includes a playback interface consisting of a manager API,a package manager API, a player API, a time API, a time base API, asystem time base API, and a media locator API. In addition, an eventlistener interface is included that defines objects to receive updateevents from players. A protocol handler interface is also included thatdefines classes to handle data delivery protocols. The resulting mobilemultimedia framework API has a memory size of less than 100 kilobytes.An exceptions interface that defines exception classes for the API canalso be included.

Advantageously, the embodiments of the present invention provide amobile multimedia framework having a greatly reduced footprint. Hence,the embodiments of the present invention can be efficiently used inmobile devices having reduced processing power and memory. The memorysize of the embodiments of the present invention is less than 200kilobytes, and often less than 30 kilobytes. The actual size dependingupon the functionality provided. Other aspects and advantages of theinvention will become apparent from the following detailed description,taken in conjunction with the accompanying drawings, illustrating by wayof example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further advantages thereof, may best beunderstood by reference to the following description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a diagram showing a prior art Java media system;

FIG. 2 is a block diagram showing the mobile multimedia frameworksystem, in accordance with an embodiment of the present invention;

FIG. 3 is a block diagram showing a mobile multimedia framework system300, in accordance with an embodiment of the present invention;

FIG. 4 is an interface block diagram showing a mobile Java multimediaframework module, in accordance with an embodiment of the presentinvention;

FIG. 5 is a block diagram showing an exemplary JMF light API, inaccordance with an embodiment of the present invention;

FIG. 6A is a diagram illustrating playback interface definitions, inaccordance with an embodiment of the present invention;

FIG. 6B is a diagram illustrating control definitions, in accordancewith an embodiment of the present invention;

FIG. 6C is a diagram illustrating event listener definitions, inaccordance with an embodiment of the present invention;

FIG. 6D is a diagram illustrating error list definitions, in accordancewith an embodiment of the present invention;

FIG. 6E is a diagram illustrating exception definitions, in accordancewith an embodiment of the present invention;

FIG. 6F is a diagram illustrating event definitions, in accordance withan embodiment of the present invention;

FIG. 6G is a diagram illustrating protocol handler definitions, inaccordance with an embodiment of the present invention; and

FIG. 7 is a flowchart showing a method for creating a JMF light API, inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An invention is disclosed for a mobile multimedia Java Framework. Thepresent invention provides a Java based multimedia framework capable ofoperating on mobile devices having reduced processing capability, suchas cell phones, PDAa, and Java-enabled car “Telematics”. In thefollowing description, numerous specific details are set forth in orderto provide a thorough understanding of the present invention. It will beapparent, however, to one skilled in the art that the present inventionmay be practiced without some or all of these specific details. In otherinstances, well known process steps have not been described in detail inorder not to unnecessarily obscure the present invention.

FIG. 1 was described in terms of the prior art. FIG. 2 is a blockdiagram showing the mobile multimedia framework system 200, inaccordance with an embodiment of the present invention. The mobilemultimedia framework system 200 include an application layer 204, amobile Java multimedia framework module 206, a Java virtual machinelayer 208, an operating system layer 210, and a hardware layer 212. Itshould be noted that other functional layers may be present to providenecessary functionality specific to the native environment, as will beapparent to those skilled in the art.

The hardware layer 212 represents the physical hardware on which themultimedia framework operates, such as a PDA or cell phone. Inoperation, a user 202 of the mobile multimedia system 200 interacts withthe application layer 204 of the mobile multimedia system 200, which canbe written by a third party developer. Generally, the application layer204 provides the user interface for the media application, such as theplay, stop, and capture controls.

The mobile Java media framework module 206 can then be used to processcommands received by the application layer 204. As described in greaterdetail subsequently, the Java media framework module 206 includes themedia engine, codec, and other media processing modules that process thecommands received by the application layer 204.

The Java virtual machine 208 is used as an interpreter to provideportability to Java applications. In general, developers design Javaapplications as hardware independent software modules, which areexecuted Java virtual machines 208. The Java virtual machine layer 208is developed to operate in conjunction with the native operating system210 of the particular hardware 212 on which the mobile multimediaframework system 200 is to run. In this manner, Java applications 204can be ported from one hardware device to another without requiringupdating of the application code.

Unlike most programming languages, in which a program is compiled intomachine-dependent, executable program code, Java classes are compiledinto machine independent byte-code class files which are executed by amachine-dependent virtual machine. The virtual machine provides a levelof abstraction between the machine independence of the byte-code classesand the machine-dependent instruction set of the underlying computerhardware. A class loader is responsible for loading the byte-code classfiles as needed, and an interpreter or just-in-time compiler providesfor the transformation of byte-codes into machine code.

More specifically, Java is a programming language designed to generateapplications that can run on all hardware platforms, small, medium andlarge, without modification. Developed by Sun, Java has been promotedand geared heavily for the Web, both for public Web sites and intranets.Generally, Java programs can be called from within HTML documents orlaunched standalone. When a Java program runs from a Web page, it iscalled a “Java applet,” and when run on a Web server, the application iscalled a “servlet.”

Java is an interpreted language. The source code of a Java program iscompiled into an intermediate language called “bytecode”. The bytecodeis then converted (interpreted) into machine code at runtime. Uponfinding a Java applet, the Web browser invokes a Java interpreter (JavaVirtual Machine), which translates the bytecode into machine code andruns it. Thus, Java programs are not dependent on any specific hardwareand will run in any computer with the Java Virtual Machine software. Onthe server side, Java programs can also be compiled into machinelanguage for faster performance. However a compiled Java program loseshardware independence as a result.

Although the present invention is described based on the Javaprogramming language, other programming languages may be used toimplement the embodiments of the present invention, such as other objectoriented programming languages. Object-oriented programming is a methodof creating computer programs by combining certain fundamental buildingblocks, and creating relationships among and between the buildingblocks. The building blocks in object-oriented programming systems arecalled “objects.” An object is a programming unit that groups together adata structure (instance variables) and the operations (methods) thatcan use or affect that data. Thus, an object consists of data and one ormore operations or procedures that can be performed on that data. Thejoining of data and operations into a unitary building block is called“encapsulation.”

An object can be instructed to perform one of its methods when itreceives a “message.” A message is a command or instruction to theobject to execute a certain method. It consists of a method selection(name) and a plurality of arguments that are sent to an object. Amessage tells the receiving object what operations to perform.

One advantage of object-oriented programming is the way in which methodsare invoked. When a message is sent to an object, it is not necessaryfor the message to instruct the object how to perform a certain method.It is only necessary to request that the object execute the method. Thisgreatly simplifies program development.

Object-oriented programming languages are predominantly based on a“class” scheme. A class defines a type of object that typically includesboth instance variables and methods for the class. An object class isused to create a particular instance of an object. An instance of anobject class includes the variables and methods defined for the class.Multiple instances of the same class can be created from an objectclass. Each instance that is created from the object class is said to beof the same type or class.

A hierarchy of classes can be defined such that an object classdefinition has one or more subclasses. A subclass inherits its parent's(and grandparent's etc.) definition. Each subclass in the hierarchy mayadd to or modify the behavior specified by its parent class.

To illustrate, an employee object class can include “name” and “salary”instance variables and a “set_salary” method. Instances of the employeeobject class can be created, or instantiated for each employee in anorganization. Each object instance is said to be of type “employee.”Each employee object instance includes the “name” and “salary” instancevariables and the “set_salary” method. The values associated with the“name” and “salary” variables in each employee object instance containthe name and salary of an employee in the organization. A message can besent to an employee's employee object instance to invoke the“set_salary” method to modify the employee's salary (i.e., the valueassociated with the “salary” variable in the employee's employeeobject).

An object is a generic term that is used in the object-orientedprogramming environment to refer to a module that contains related codeand variables. A software application can be written using anobject-oriented programming language whereby the program's functionalityis implemented using objects. Examples of object-oriented programminglanguages include C++ as well as Java.

FIG. 3 is a block diagram showing a mobile multimedia framework system300, in accordance with an embodiment of the present invention. Themobile multimedia framework system 300 include an application layer 204,a mobile Java multimedia framework module 206, a Java virtual machinelayer 208, an operating system layer 210, and a hardware layer 212. Themobile Java multimedia framework module 206 includes a media engine 302,data sources 304, a codec 306, renderer 308, and a parser 310. Alsoincluded in the mobile Java multimedia framework module 206 is a MPEGmodule 312, a MIDI module 314, and a FLASH module 316. It should benoted that other media modules can be included as needed by theapplications.

The a mobile Java multimedia framework module 206 is a set of multimediaAPIs and implementations designed to playback multimedia in a variety ofprotocols and formats, such as a QuickTime Cinepak movie over the HTTP(Hypertext Transfer Protocol) protocol. The Java Media Frameworkspecifies the concept of a “player,” a unit to playback multimedia data.As illustrated in FIG. 3, within the Java multimedia framework module206 are implementations of the three main stages of the media processingpipeline: the parser 310, the decoder 306 and the renderer 308. Theparser 310 transforms the media data into a compressed and/or encodedmedia data file or stream. Decoder (codec) 306 transforms the compressedand/or encoded media data into raw (decompressed and unencoded) mediadata 305 for use by renderer 306. Renderer 306 processes the raw mediadata into media output for display or presentation on an output device,such as a monitor for graphics or a speaker for audio.

The mobile Java multimedia framework module 206 of the embodiments ofthe present invention is an order of magnitude smaller than conventionalmedia modules. As previously mentioned, prior art media frameworks aretypically 2–3 megabytes in size. Advantageously, the embodiments of thepresent invention, however, are less than 200 kilobytes, often less than30 kilobytes. The actual size depending upon the functionality provided.

To reduce the size of the mobile Java multimedia framework module 206,the embodiments of the present invention optimize the operation of theframework module. To this end, an embodiment of the present inventionconverts all push data deliver protocols to pull data deliveryprotocols. In a push data delivery protocol, data is constantlyprovided, without needing to be requested. An example of a push datadelivery protocol is a television broadcast. The television broadcast isalways available, without needing to be requested. Moreover, the rate ofthe data delivery is controlled by the server; or the broadcast stationin this example. An example of a pull data delivery protocol is a WorldWide Web site. When a user enters a URL in a web browser, the user isrequesting the data from the web site to be sent to the user's computer.The rate of the data delivered in the pull scenario is controlled by theclient and limited by the network bandwidth. A push data deliveryprotocol can almost always be converted to a pull protocol (and viceversa) by means of using data buffering and adding an additionalprocessing thread to control the data flow. Hence the push data protocolcan be eliminated from the framework as a size reduction measure withoutsacrificing any necessary functionalities. Thus, the embodiments of thepresent invention convert all data delivery to a pull data deliveryprotocol.

The embodiments of the present invention also remove the master/slaveparadigm to reduce the size of the mobile Java multimedia frameworkmodule 206. It should be noted, however, that master/slave paradigmsbetween program modules can still be created at the application level204. Thus, the embodiments of the present invention move themaster/slave relationship functionality from the mobile Java multimediaframework module 206 to the application layer 204, resulting in areduction of the mobile Java multimedia framework module 206 size.Moreover, most media content displayed using the mobile Java multimediaframework module 206 includes both audio and video if they are to be runtogether. In other words, most media is not separated. However, when themaster/slave paradigm is needed, such as when the audio and video areseparated, the master/slave paradigm can be provided at the applicationlevel 204.

The embodiments of the present invention further convert allasynchronous operations into synchronous operations to reduce the sizeof the mobile Java multimedia framework module 206. An example of anasynchronous operation is an email request. When a user sends email, theuser can continue with other operations while awaiting a reply to theemail. The user is not prevented from performing further operations ontheir computer until the reply is received. An example of a synchronousoperation is a telephone call. During a telephone call the user waitsfor an immediate reply to the call.

From a programming point of view, if a start video function is called,two separate events occur under the asynchronous and synchronous models.Using an asynchronous model, the start video function would immediatelyreturn and a listener function would execute. The listener functionwould provide an event that informs the program that video has started.However, during the time the listener function is awaiting the videostart, the module calling the start video function can continueexecuting other operations. Using a synchronous model, the start videocall would stop operation of the calling module until the video isactually started.

The asynchronous model is appropriate when delays are expected duringoperation of the system, such as when setup operations are required toexecute the modules. The synchronous model is appropriate when delaysare not expected, or are of short duration. Since mobile devices aregenerally design to respond quickly with little delay, the embodimentsof the present invention preferably do not utilize an asynchronousmodule to implement the mobile Java multimedia framework module 206.However, an asynchronous module can be used at the application layer204, similar to the master/slave paradigm.

As mentioned above the mobile Java multimedia framework module 206includes a media engine 302 that uses the data sources 304, codec 306,renderer 308, and parser 310 to process media provided by theapplication layer 204. In addition, specialized players are included,such as an MPEG player 312, MIDI player 314, and FLASH player 316. Itshould be noted that other specialize players may be included in themobile Java multimedia framework module 206, desired by the developer.

The media engine 302 is used as a generic media data processor, whilethe specialized players are used to process data specific to theparticular specialized player. For example, in the system 300 of FIG. 3,all MPEG media is processed using the MPEG player 312. Each specializedplayer includes its own specialized media engine, parser, codec, andrender optimized to process MPEG media.

Below the mobile Java multimedia framework module 206 is a Java virtualmachine (JVM) 208. In some embodiments of the present invention portionsof the mobile Java multimedia framework module 206, such as the codec306, can bypass the JVM 208 and interface directly the native operatingsystem 210, which interfaces with the native hardware 212. This allowsfor increased speed and efficiency when needed.

FIG. 4 is an interface block diagram showing a mobile Java multimediaframework module 206, in accordance with an embodiment of the presentinvention. The interface diagram of FIG. 4 illustrates the programminginterface for the mobile Java multimedia framework module 206. Morespecifically, the mobile Java multimedia framework module 206 includes aJava media framework (JMF) light application programming interface 206 aand a JMF light implementation module 206 b.

The mobile Java multimedia framework module 206 is developed in anindependent piecewise manner by establishing the JMF light applicationprogramming interface (API) for components of the JMF lightimplementation module 206 b. The JMF light API 206 a refers to themethods of the JMF light implementation module 206 b that are accessibleby the applications executing on the application layer. The JMF lightAPI 206 a further defines the format by which those methods are invoked.The particular implementation of those methods is important only withrespect to the design of the particular component. Each component of theJMF light implementation module 206 b is designed individually toimplement the JMF light API 206 a and any internal functions, and tointerface with the APIs of the other components of the application.Typically, these components comprise one or more objects forming theapplication.

FIG. 5 is a block diagram showing an exemplary JMF light API 206 a, inaccordance with an embodiment of the present invention. The JMF lightAPI 206 a includes format definitions for a plurality of methodsaccessible by applications using the JMF light API 206 a. For example,the JMF light API 206 a includes playback interface definitions 500,control definitions 502, event listener definitions 504, error listdefinitions 506, exception definitions 508, event definitions 510, andprotocol handler definitions 512. These definitions define the format bywhich those methods are invoked by applications. As mentioned above,each component of the JMF light implementation module 206 b is designedindividually to implement the JMF light API 206 a and any internalfunctions, and to interface with the APIs of the other components of theapplication. Typically, these components comprise one or more objectsforming the application.

The Playback interface 500 is the top-level entry point to the API. Itprovides functions to create a Player object and the implementation ofthe various media Players. The player implementations provide themethods to control the basic playback functions, such as start, stop,and set media time. The Control interface 502 provides objects tocontrol other advance playback functions. Examples of such functions arecontrolling audio gain, data caching, and video frame stepping.

The Event Listener interface 504 provides the objects to receive updateevents from the players. The Error List interface 506 contains thedefinition of the error classes, and the Exceptions interface 508contains the definition of the exception classes. The Events interface510 contains the definition of the event classes, while the ProtocolHandler interface 514 provides the classes to handle the data deliveryprotocols.

FIGS. 6A–6G illustrate an exemplary JMF light API 206 a, in accordancewith an embodiment of the present invention. The MIDP prototype is anexemplary JMF light implementation. FIGS. 6A–6G list the API definitionsof the multimedia framework. Applications use these classes to createand control media playback. Additional implementation classes can beused to support the API by providing playback for Wave and MP3 audiofiles, QuickTime and MPEG-4 video files and Flash media formats.

FIG. 6A is a diagram illustrating playback interface definitions 500, inaccordance with an embodiment of the present invention. In particular,the Manager.java API definition is a top-level class to manage andcreate media Players. PackageManager.java stores and maintains thepackage prefixes to find the media Players, and Player.java is the mediaPlayer interface. The time.java definition defines the time object, andTimeBase.java defines the time base for synchronizing the mediapresentation. SystemTimeBase.java is the time base implemented using thesystem clock, and MediaLocator.java is the interface to specify thelocation of the media.

FIG. 6B is a diagram illustrating control definitions 502, in accordancewith an embodiment of the present invention. In the control definitions502, Control.java is a base class for all control types, whileControls.java is a base class for all objects that support advancecontrols. Regarding the actual controls, CachingControl.java is acontrol for caching, and GainControl.java is a control for audio gain.

FIG. 6C is a diagram illustrating event listener definitions 504, inaccordance with an embodiment of the present invention. The eventlistener definitions 504 include PlayerListener.java, which is an eventlistener for the Player, and GainChangeListener.java, which is alistener for gain change events.

FIG. 6D is a diagram illustrating error list definitions 506, inaccordance with an embodiment of the present invention. As shown in FIG.6D, the error list definitions 506 includes PlayerError.java, which arethe errors generated by the Player. Similarly, FIG. 6E is a diagramillustrating exception definitions 508, in accordance with an embodimentof the present invention. PlayerException.java is a base class for thefollowing Player exceptions. IncompatibleTimeBaseException.java is anexception generated by an incompatible time base is used,NoPlayerException.java is an exception when no player can be found forthe given media, and NoDataSource.java is an exception when noDataSource can be found for the given media.

FIG. 6F is a diagram illustrating event definitions 510, in accordancewith an embodiment of the present invention. The event definitions 510include AudioDeviceUnvailableEvent.java, which is an event when theaudio device is not available, PlayerEvent.java, which is a base classfor all player events, and CachingControlEvent.java, which are eventsfor caching. Further events included in the event definitions 510 isStopEvent.java, which is an event when the player is stopped,GainChangeEven.java, which is an event when the audio gain is changed,PlayerErrorEvent.java, which is an event when an error occurs in theplayer, and DurationUpdateEvent.java, which is an event when theduration is updated. In addition, The EndOfMediaEvent.java is an eventwhen End of Media occurs, InternalErrorEvent.java is an event when aninternal error occurs, SizeChangeEvent.java is an event when the videosize is changed, and StopAtTimeEvent.java is an event when the player isstopped due to a preset stop time.

FIG. 6G is a diagram illustrating protocol handler definitions 512, inaccordance with an embodiment of the present invention. The protocolhandler definitions 512 include Seekable.java, which is an interface forseekable type of DataSource, DataSource.java, which is a class to readdata from, ContentDescriptor.java, which describes the data type, andSourceStream.java, which is an abstraction of a data stream inside aDataSource.

FIG. 7 is a flowchart showing a method 700 for creating a JMF light API,in accordance with an embodiment of the present invention. In an initialoperation 702, preprocess operations are performed. Preprocessoperations include determining a programming language in which toimplement the JMF light API and other preprocess operations that will beapparent to those skilled in the art.

In operation 704, a type of implementation requiring access tomultimedia content is determined. To design the API, the general type ofhardware on which the API will operate is determined. This includesdetermining the amount of memory and processing power that will beavailable for use by the API, the API implementation, and theapplication using the API.

Next, in operation 706, the API component access parameters are set tosynchronous. As mentioned above, the embodiments of the presentinvention convert all asynchronous operations into synchronousoperations to reduce the size of the mobile Java multimedia frameworkmodule. The asynchronous model is appropriate when delays are expectedduring operation of the system, such as when setup operations arerequired to execute the modules. The synchronous model is appropriatewhen delays are not expected, or are of short duration. Since mobiledevices are generally design to respond quickly with little delay, theembodiments of the present invention preferably do not utilize anasynchronous module to implement the mobile Java multimedia frameworkmodule. However, an asynchronous module can be used at the applicationlayer.

In operation 708, the API components are set to pull only. Theembodiments of the present invention convert push data deliver protocolsto pull data delivery protocols. In a push data delivery protocol, datais constantly provided, without needing to be requested. Thus, theembodiments of the present invention convert all data delivery to a pulldata delivery protocol to further reduce the size of the JMF light API.

In operation 710, master/slave functionality is removed from thecomponents of the JMF API. The embodiments of the present invention alsoremove master/slave paradigm to reduce the size of the mobile Javamultimedia framework module. It should be noted, however, thatmaster/slave paradigms between program modules can still be created atthe application level. Thus, the embodiments of the present inventionmove the master/slave relationship functionality from the mobile Javamultimedia framework module to the application layer, resulting in areduction of the mobile Java multimedia framework module size. Moreover,most media content displayed using the mobile Java multimedia frameworkmodule includes both audio and video if they are to be run together. Inother words, most media is not separated. However, when the master/slaveparadigm is needed, such as when the audio and video are separated, themaster/slave paradigm can be provided at the application level.

The controls for playback are then optimized in operation 712.Preferably the set of controls included in the framework is reduced to asmall set of controls that are directly related to playback on smalldevices. These include audio gain, caching and video frame positioningcontrols.

Post process operations are performed in operation 716. Post processoperations include installing the completed API on the native hardwareand other post process operations that will be apparent to those skilledin the art. Advantageously, the embodiments of the present inventionprovide a mobile multimedia framework having a greatly reducedfootprint. Hence, the embodiments of the present invention can beefficiently used in mobile devices having reduced processing power andmemory.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced within the scope of theappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

1. A mobile multimedia framework application program interface (API)capable of operation in mobile hardware devices, the mobile multimediaframework API consisting of: a playback interface, a control interface,an event listener interface, an error list interface, an exceptionsinterface, an events interface, and a protocol handler interface,wherein a memory size of the mobile multimedia framework API is lessthan 100 kilobytes.
 2. A mobile multimedia framework API as recited inclaim 1, wherein the playback interface is a top-level entry point tothe API for an application.
 3. A mobile multimedia framework API asrecited in claim 2, wherein the playback interface further defines startand stop playback functionality.
 4. A mobile multimedia framework API asrecited in claim 1, wherein the control interface defines advanceplayback functions.
 5. A mobile multimedia framework API as recited inclaim 1, wherein the event listener interface defines objects to receiveupdate events from players.
 6. A mobile multimedia framework API asrecited in claim 1, wherein the error list interface defines errorclasses for the API.
 7. A mobile multimedia framework API as recited inclaim 1, wherein the exceptions interface defines exception classes forthe API.
 8. A mobile multimedia framework API as recited in claim 1,wherein the protocol handler interface defines classes to handle datadelivery protocols.
 9. A mobile multimedia framework application programinterface (API) capable of operation in mobile hardware devices, themobile multimedia framework API comprising: a playback interfaceconsisting of a manager API, a package manager API, a player API, a timeAPI, a time base API, a system time base API, and a media locator API;an event listener interface; and a protocol handler interface, wherein amemory size of the mobile multimedia framework API is less than 100kilobytes.
 10. A mobile multimedia framework API as recited in claim 9,wherein the protocol handler interface defines classes to handle datadelivery protocols.
 11. A mobile multimedia framework API as recited inclaim 9, further comprising a control interface.
 12. A mobile multimediaframework API as recited in claim 11, wherein the control interfacedefines advance playback functions.
 13. A mobile multimedia frameworkAPI as recited in claim 9, further comprising an error list interface.14. A mobile multimedia framework API as recited in claim 13, whereinthe error list interface defines error classes for the API.
 15. A mobilemultimedia framework API as recited in claim 9, further comprising anexceptions interface.
 16. A mobile multimedia framework API as recitedin claim 15, wherein the exceptions interface defines exception classesfor the API.
 17. A mobile multimedia framework application programinterface (APl) capable of operation in mobile hardware devices, themobile multimedia framework API comprising: a playback interfaceconsisting of a manager API, a package manager API, a player API, a timeAPI, a time base API, a system time base API, and a media locator API;an event listener interface that defines objects to receive updateevents from players; and a protocol handler interface that definesclasses to handle data delivery protocols, wherein a memory size of themobile multimedia framework API is less than 100 kilobytes.
 18. A mobilemultimedia framework API as recited in claim 17, further comprising anexceptions interface.
 19. A mobile multimedia framework API as recitedin claim 18, wherein the exceptions interface defines exception classesfor the API.